Use the discriminant to describe the roots of each equation. Then select the best description.

x2 - 5x - 4 = 0

double root
real and rational root
real and irrational root
imaginary root

Respuesta :

Answer:

Real and irrational root

Step-by-step explanation:

Since a quadratic equation [tex]ax^2+bx+c[/tex],

Has two real different roots,

If the value of discriminant [tex]D=b^2-4ac>0[/tex]

Has two equal real roots,

If [tex]D=0[/tex]

Has two imaginary roots,

If [tex]D<0[/tex]

Here, the given equation,

[tex]x^2-5x-4=0[/tex]

[tex]D=(-5)^2-4\times 1\times -4=25+16= 41>0[/tex]

Hence, the equation has the two unequal real roots,

Now, √D is an irrational number ( Which can not be expressed in the form of p/q in which q≠0 )

Therefore, the given equation has real and irrational root,

Third option is correct.